How would you include a repeat number when keymapping a Vintage command? For example, you could remap the ‘i’ key to move up one line with:

	{ "keys": "i"], "command": "set_motion", "args": {
		"motion": "move",
		"motion_args": {"by": "lines", "forward": false, "extend": true },
		"linewise": true },
		"context": {"key": "setting.command_mode"}]
	}

How would you remap the ‘I’ (uppercase-i) key to move up, say, 20 lines?